ANALYSIS OF OLEFINIC GASOLINES WITH MULTIDIMENSIONAL GAS-CHROMATOGRAPHY

This paper evaluates the strengths and weaknesses of a multidimensional Paraffin-lso/normal-Olefin-Naphthene-Aromatic (PIONA) analyzer for olefinic naphthas. These complex materials, which can overwhelm conventional capillary gas chromatographic (GC) techniques, are analyzed with reasonably good accuracy (generally within 0.2 wt % for nonolefinic compounds, and approximately 0.5 wt % for olefinic species) using the PIONA instrument. Although not a speciation technique, this multidimensional GC method provides accurate class and carbon number information from C4 through C11. Using traditional single capillary GC, it is difficult to resolve all the species present in olefinic sample types beyond approximately C6. Limitations of the PIONA instrument, including non-idealities of the reversible olefin trap, are discussed. Suggestions for improved aromatic characterization and analysis of oxygenated gasolines are also presented. © 1994 Oxford University Press.